Effect of cycle time and airflow in biological nitrogen removal from poultry slaughterhouse wastewater using sequencing batch reactor

Abstract

This study aimed to evaluate the influence of airflow (0.25, 0.50 and 0.75 L.L -1 .min -1 ) and cycle time (10.45 h, 14.25 h and 17.35 h) on a sequencing batch reactor (SBR) performance in promoting nitrification and denitrification of poultry slaughterhouse wastewater. The operational stages included feeding, aerobic and anoxic reactions, sedimentation and discharge. SBR was operated in a laboratory scale with a working volume of 4 L, keeping 25% of biomass retained inside the reactor as inoculum for the next batch. In the anoxic stage, C: N ratio was maintained between 5 and 6 by adding cassava starch wastewater. A factorial design (2 2 ) with five repetitions was designed at the central point to evaluate the influence of cycle time and airflow on total inorganic nitrogen removal (N-NH 4 + +N-NO 2 -+N-NO 3 -) and in the whole process (nitrification and denitrification). The highest total inorganic nitrogen removal (93.3%) was observed for airflow of 0.25 L.L -1 .min -1 and a cycle time of 14.25 h. At the end of the experiment, the sludge inside the reactor was characterized by fluorescent in situ hybridization (FISH), indicating the presence of ammonia and nitrite oxidizing bacteria.KEYWORDS: nitrification, denitrification, response surface methodology, fluorescent in situ hybridization. EFEITO DO TEMPO DE CICLO E DA VAZÃO DE AR NA REMOÇÃO BIOLÓGICA DE NITROGÊNIO DE EFLUENTE DE ABATEDOURO DE AVES UTILIZANDO REATOR EM BATELADAS SEQUENCIAISRESUMO: Este trabalho teve por objetivo avaliar a influência da vazão de ar (0,25; 0,50 e 0,75 L.L -1 .min -1 ) e do tempo de ciclo (10h45; 14h25 e 17h35) no desempenho de um reator em bateladas sequenciais (RBS) em promover a nitrificação e a desnitrificação de água residuária de abatedouro de aves. A operação contemplou as etapas de alimentação, reação aerada e anóxica, sedimentação e descarte. O RBS foi operado em escala de bancada com volume útil de 4 L, mantendo-se 25% do volume do reator como inóculo em cada batelada. Na fase anóxica, a relação C:N foi mantida entre 5 e 6, adicionando-se água residuária do processo de obtenção de fécula de mandioca. Elaborou-se um planejamento fatorial (2 2 ) com cinco repetições, no ponto central, para verificar a influência dos fatores, o tempo de ciclo e a vazão de ar, na variável resposta remoção de nitrogênio inorgânico total (N-NH 4 + +N-NO 2 -+N-NO 3 -), no processo completo (nitrificação e desnitrificação). A maior remoção de nitrogênio inorgânico total (93,3%) foi observada quando se utilizou vazão de ar de 0,25 L.L -1 .min -1 e tempo de ciclo de 14h25. No final do experimento, o lodo do reator foi caracterizado através de hibridização fluorescente in situ (FISH), indicando a presença de bactérias oxidadoras de amônia e de nitrito.

Influence of recirculation rate on the performance of a combined anaerobic-aerobic reactor applied to the removal of carbon and nitrogen from poultry slaughterhouse wastewater

“…Author(s) agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License such as the initial concentration of ammonia nitrogen, the carbon to nitrogen ratio, the air flow and the cycle time (Andrade et al, 2010;Kummer et al, 2011;Dallago et al, 2012;Mees et al, 2011;Lima, et al, 2014;Lopes, et al, 2015).…”

Nitrogen Source Stabilization of Quorum Sensing in the Pseudomonas aeruginosa Bioaugmentation Strain SD-1

“…Likewise, if casein is the sole source of nitrogen and carbon, bacteria overexpress QS-regulated traits (13) and are more susceptible to invasion by cheaters. This apparent ability of the nitrogen source to modulate QS led us to query whether different sources of nitrogen, including NH 4 Cl, NaNO 3 , and NaNO 2 , which are common inorganic nitrogen sources in wastewater, might have an effect on bacterial population stability (19).…”